Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F3/00—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow
  • G01F3/02—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow with measuring chambers which expand or contract during measurement
  • G01F3/04—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow with measuring chambers which expand or contract during measurement having rigid movable walls
  • G01F3/14—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow with measuring chambers which expand or contract during measurement having rigid movable walls comprising reciprocating pistons, e.g. reciprocating in a rotating body
  • G01F3/16—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow with measuring chambers which expand or contract during measurement having rigid movable walls comprising reciprocating pistons, e.g. reciprocating in a rotating body in stationary cylinders
• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62C—FIRE-FIGHTING
  • A62C99/00—Subject matter not provided for in other groups of this subclass
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M65/00—Testing fuel-injection apparatus, e.g. testing injection timing ; Cleaning of fuel-injection apparatus
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M65/00—Testing fuel-injection apparatus, e.g. testing injection timing ; Cleaning of fuel-injection apparatus
  • F02M65/002—Measuring fuel delivery of multi-cylinder injection pumps
• • G—PHYSICS
  • G07—CHECKING-DEVICES
  • G07C—TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
  • G07C9/00—Individual registration on entry or exit
  • G07C9/20—Individual registration on entry or exit involving the use of a pass
  • G07C9/28—Individual registration on entry or exit involving the use of a pass the pass enabling tracking or indicating presence

Definitions

• the invention relates to a device for measuring time-resolved volumetric flow processes, in particular injection processes in internal combustion engines, with a translational volume difference transducer, which essentially consists of a piston arranged in a measuring chamber and a detection device receiving the deflection of the piston, which is connected to an evaluation unit.
• DE 31 39 831 A1 describes a method in which a measuring piston is moved through the amount of fuel injected into a measuring chamber. The amount of fuel injected is inferred from the piston travel. After a certain number of individual injections, the volumetric piston is returned to its starting position. The end positions of the volumetric flask are recorded. In this method, however, due to the inertia of the piston mass and the friction that occurs, measurement inaccuracies are too great for today's conditions.
• DE 39 16 419 A1 describes an electromagnetically controlled measuring device which further develops the device according to DE 31 39 831 A1, the measuring chamber being emptied after each injection.
• DE 41 30 394 A1 proposes an injection quantity measuring device in which the injection takes place in a closed pressure vessel. After measuring the pressure in each case after pre-injection or main injection in this pressure vessel, a valve is switched again so that the injected quantity is discharged into a measuring range, in which there is in turn a piston moved by the liquid, so that from the movement of the Piston can be concluded on the injected volume.
• a valve is switched again so that the injected quantity is discharged into a measuring range, in which there is in turn a piston moved by the liquid, so that from the movement of the Piston can be concluded on the injected volume.
• DE 1 798 080 describes an electronically controlled flow measuring and metering device which can measure flows with high accuracy in a large measuring range.
• This measuring device is optimally suited for the immediate measurement of flows due to its extremely low inertia, but is not able to display flow rate information synchronous to the cycle. This means that it is not possible to show the exact courses of the injection processes to be measured and their periodicity at the same time as the working cycle of a petrol or diesel engine.
• a continuously operating flow measuring device which is attached downstream of the injection devices, is also disclosed by DE 33 02 059.
• the injection nozzle injects into a channel that leads to a gear pump and to which a second channel is connected in parallel, in which a piston is slidably guided. These two channels together form the necessary injection volume, which can be changed by the movement of the piston.
• the path of the piston is measured on the one hand and on the other hand fed to a control motor for speed control of the gear pump via an electrical control circuit.
• this device should also be able to be positioned in front of an injection valve as far as possible and should be able to on one continuously running engine to measure injection quantities and courses. This enables the stability of the injections from cycle to cycle and from injector to injector to be assessed quantitatively using statistical parameters. Accordingly, measured values such as the injection rate or the partial quantities of multiple injections, as well as the total quantity injected over a longer course, must be made visible.
• a pressure sensor is arranged in the measuring chamber, which pressure sensor is connected to the evaluation unit in such a way that the measurement values of the pressure sensor in the evaluation unit correct the measured values of the detection device Flow rate takes place.
• the translational volume difference transducer is assigned a rotary displacer which is driven by a motor Dependence on the applied volume difference is driven, the measuring chamber being arranged in an inlet channel, which opens into an outlet channel behind the translational volume difference sensor and the rotary displacer is arranged in a bypass line to the translational volume difference sensor, the rotary displacer being controlled in this way that the speed of the displacer is constant during a work cycle and essentially corresponds to the mean flow over the entire work cycle.
• a sawtooth-shaped signal results as the piston path, since the movement of the piston is composed of a continuous movement due to the rotational speed of the rotary displacer and a discontinuous movement due to the individual injections.
• a work cycle corresponds, for example, to a pre-injection, a main injection and a post-injection.
• the detection device preferably consists of a sensor, the voltage generated of which represents a measure of the deflection of the piston and which continuously detects the deflection of the piston in the measuring chamber. Flow changes are thus recognized by a corresponding voltage change on the sensor, and by transferring them to the evaluation unit, these results can be converted into an injection quantity and an injection course in a simple manner. Due to the continuous detection of the deflection, such a device can also be used on a running engine with many successive injection processes, that is to say work cycles, since it is no longer necessary to empty the measuring chambers, for example by means of valves, as in the prior art. Furthermore, such a device can be installed both in front of and behind a fuel injection valve.
• the piston has the same specific weight as the measuring liquid. Because the specific weight of the piston corresponds to that of the measuring liquid and the piston is freely movable, flow changes are recognized almost without time delays due to the corresponding voltage change on the sensor, which makes it possible to show the time profiles of an individual injection.
• a temperature sensor can be arranged in the measuring chamber, which is connected to the evaluation unit, so that the temperature in the room can also be included in the calculation, which further increases the accuracy of the measurement, since the piston travel is based on the pressure and temperature signal can be converted into an ideal piston travel, which would result in isobaric and isothermal conditions during the measurement.
• the compressibility module of the fluid as a function of temperature and pressure is also taken into account accordingly.
• the sensor of the translational volume difference transducer can be an optical, inductive or working according to the eddy current principle. These sensors work almost without inertia and therefore deliver very precise measured values.
• the motor is designed as a servo motor and has a motion sensor which is connected to the evaluation unit and control electronics, the signal from the motion sensor representing a measure of the rotational speed of the rotary displacer.
• the rotary displacer can be controlled in a simple manner via the signals of, for example, the optical sensor and the motion sensor.
• the movement sensor is advantageously designed as a pulse generator disk, which enables a reliable and very precise determination of the displacement speed.
• the hydraulic length from a fuel injection valve to the input side of the rotary displacer is equal to the hydraulic length to the output side of the rotary displacer, which makes it possible to operate the displacer without an applied pressure difference and thus to be able to determine the amount injected up to that point exactly at any time.
• the compressibility of the fluid can cause pressure waves to propagate through the entire measurement setup.
• the flow meter is arranged according to the invention between at least one fuel injection valve and a runtime pipe.
• a device is thus created which makes it possible to measure volumetric flow processes continuously and in a temporally resolved manner, the structure being very simple and nevertheless very high measuring accuracies being achievable. In this way, qualitatively and quantitatively precise statements about injection processes and injection quantities and their stability can be made. Measured values such as the injection rate or the partial quantities of multiple injections and the total quantity injected in the same or a longer period of time can be made visible with this device.
• the rotary displacer used for the continuous measurement can be calibrated in a conventional manner, so that by correlating the measured values, the single-shot measurements can also be calibrated in a comparatively simple manner.
• a device according to the invention is shown in the figures and is described below.
• Figure 1 shows schematically the structure of the measuring device according to the invention behind an injection valve.
• Figure 2 shows an example of typical piston profiles without a continuous portion by the gear pump during a work cycle with two pre-injections, one main injection and two post-injections, and the resulting injection quantity profile.
• FIG. 1 shows a structure for measuring injection processes in internal combustion engines with a device according to the invention for measuring time-resolved volumetric flow processes. It consists of one a flow-generating device, not shown, in this case usually a high-pressure pump and a fuel injection valve 1, via which fuel is injected into the measuring device 2.
• the measuring device 2 consists of an inlet channel 3 in which a measuring chamber 4 is arranged, in which a piston 5 is again freely displaceable, the piston 5 having the same specific weight as the measuring liquid, ie the fuel.
• This piston 5 in the measuring chamber 4 serves as a translational volume difference sensor.
• a sensor 6 is arranged on the measuring chamber 4, which is in operative connection with the piston 5 and in which a voltage dependent on the size of the deflection of the piston 5 is generated by the deflection of the piston 5.
• a bypass line 7 which branches off the translational volume difference transducer and branches off as shortly as possible behind the injection valve 1, has a rotary displacer in the form of a gear pump 8.
• the gear pump 8 is driven by a servo motor 10 via a clutch 9. Both the inlet line 3 and the bypass line 7 open into an outlet channel 11.
• the sensor 6 is connected to an evaluation unit 12, which records and processes the values of this sensor 6 and the number of revolutions of the motor 10, which is connected to a motion sensor in the form of a pulse generator 13.
• the sensor 6 is designed here as an optical sensor.
• a pressure sensor 14 and a temperature sensor 15 are arranged, which continuously measure the pressures and temperatures occurring in this area and in turn feed them to the evaluation unit 12.
• a runtime tube (not shown) is arranged behind the outlet channel 11 of the measuring device 2, as a result of which the pressure waves are decoupled in time from the measuring process.
• the piston 5 reacts without delay, i.e. without inertia, since it has the same specific weight as the fuel and is immediately identical to the fuel column supplied, so that its deflection is a measure of the volume the one amount of fuel injected.
• the inlet channel 3 via the piston and via the gear pump 8, since the hydraulic lengths from the injection valve 1 to the input and output sides of the gear pump 8 are kept the same.
• the gear pump 8 arranged in the bypass duct 7 is simultaneously driven at a speed which is dependent on the deflection of the piston 5 and thus on the amount of fuel injected.
• the control takes place in such a way that the rotational speed of the gear pump 8 is kept constant over a working cycle, for example pre-injection, main injection, post-injection, and only when it occurs
• the deflection of the piston 5 is thus created by superimposing a portion at a constant speed in the opposite direction to the deflection direction during an injection and a discontinuous portion during an injection.
• the evaluation unit 12 receives the corresponding signals from the pulse generator 13 on the servo motor 10 for determining the flow through the gear pump 8.
• the conversion in the electronic evaluation unit 12 takes place via a physically based model calculation, in which the actually measured piston benweg is converted with the help of the pressure and temperature signal into an ideal piston travel, which would occur during the measurement under isobaric and isothermal conditions.
• the compressibility module of the fluid as a function of temperature and pressure is also taken into account in this calculation.
• this calculation is very clearly simplified by the constant speed of rotation of the gear pump 8 and thus the continuous proportion of movement of the piston 5.
• the needle stroke 17 of the fuel injector 1 measured by inductive scanning, the piston path 18 measured by the sensor 6, the continuous portion having already been calculated out by the gear pump 8, the pressure curve 19 measured by the pressure sensor 14, which Pressure curve 19 corrected piston path 20 and the resulting injection quantity curve 21 of fuel injector 1 calculated from these data are shown over time.
• the first pilot injection 22 deflects the piston 5 in the measuring chamber 4 and increases the pressure in the measuring chamber 4. Due to the deflection of the piston 5, the pressure in the measuring chamber 4 then drops again.
• the constant movement of the gear pump 8 means that the actually measured path from which the piston path 18 is derived has a steady drop. The path actually measured is not shown.
• the pressure and piston path curves 18-21 correspondingly result in the following second pilot injection 23 as well as the main 24 and the two post-injections 25, 26.
• the gear pump 8 is regulated in such a way that the pressure and thus the actual position of the piston 5 correspond to the starting position at the end of the working cycle.
• the microsecond range Due to the direct movement of the piston 5 due to its almost non-existent inertia, changes in the microsecond range can also be measured and evaluated during the working cycle, so that this measuring device 2 is able to make comparisons between different injection valves 1 with regard to their injection quantities and in particular also to make the timing of the injection processes.
• the total flow over a certain time interval results from the output of the pulse generator 13 of the gear pump 8. The time interval is synchronized with the injections.
• the measuring device 2 described above can also be arranged upstream of the fuel injection valve 1, in which case the runtime pipe is also arranged before the flow measurement, so that the entire measuring device 2 is arranged between the high pressure pump and the fuel injection valve 1.
• This device makes it possible to measure flow processes on the running engine in front of or behind the injection valve with any number of consecutive fuel injection pulses. This makes it possible to make quantitative and high-quality statements about injection quantities, injection profiles and to assess different injection valves.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Public Health (AREA)
• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Measuring Volume Flow (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)
• Peptides Or Proteins (AREA)
• Valve Device For Special Equipments (AREA)
• Measuring Fluid Pressure (AREA)

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• 2003
  • 2003-07-10 DE DE10331228A patent/DE10331228B3/de not_active Expired - Fee Related
• 2004
  • 2004-07-06 MX MXPA06000240A patent/MXPA06000240A/es active IP Right Grant
  • 2004-07-06 EP EP04740681A patent/EP1644707B1/fr not_active Expired - Lifetime
  • 2004-07-06 AT AT04740681T patent/ATE493638T1/de active
  • 2004-07-06 WO PCT/EP2004/007353 patent/WO2005005935A1/fr not_active Ceased
  • 2004-07-06 DE DE502004012064T patent/DE502004012064D1/de not_active Expired - Lifetime
  • 2004-07-06 JP JP2006518118A patent/JP4381415B2/ja not_active Expired - Fee Related
  • 2004-07-06 CN CNB2004800197724A patent/CN100386605C/zh not_active Expired - Fee Related
  • 2004-07-06 US US10/563,955 patent/US7254993B2/en not_active Expired - Fee Related
  • 2004-07-06 KR KR1020067000530A patent/KR101095758B1/ko not_active Expired - Fee Related

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